import Vue from 'vue'
import Router from 'vue-router'
import Login from '../components/Login.vue'
import Home from '../components/Home.vue'
import Welcome from '../components/Welcome.vue'
import Users from '../components/user/Users.vue'

Vue.use(Router)

const router = new Router({
  routes: [
    { path: '/', redirect: '/login' },
    {
      path: '/home',
      component: Home,
      redirect: '/welcome',
      children: [
        { path: '/welcome', component: Welcome },
        { path: '/users', component: Users }
      ]
    },
    { path: '/login', component: Login }
  ]
})

// 挂载路由导航守卫
router.beforeEach((to, from, next) => {
  // to 将要访问的路径
  // from 代表从哪个路径跳转过来的
  // next 是一个函数，表示放行
  //     next() 放行   next('/login') 强制跳转
  if (to.path === '/login') {
    return next()
  }

  const tokenStr = window.sessionStorage.getItem('token')
  if (!tokenStr) {
    // 判断 sessionStorage 是否存在 token ,不存在就强制条转 /login 路由
    return next('/login')
  }
  next()
})
export default router
